/* ----------------------------------------------------------------------
 * Project:      CMSIS DSP Library
 * Title:        arm_mat_scale_q15.c
 * Description:  Multiplies a Q15 matrix by a scalar
 *
 * $Date:        18. March 2019
 * $Revision:    V1.6.0
 *
 * Target Processor: Cortex-M cores
 * -------------------------------------------------------------------- */
/*
 * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "arm_math.h"

/**
  @ingroup groupMatrix
 */

/**
  @addtogroup MatrixScale
  @{
 */

/**
  @brief         Q15 matrix scaling.
  @param[in]     pSrc        points to input matrix
  @param[in]     scaleFract  fractional portion of the scale factor
  @param[in]     shift       number of bits to shift the result by
  @param[out]    pDst        points to output matrix structure
  @return        execution status
                   - \ref ARM_MATH_SUCCESS       : Operation successful
                   - \ref ARM_MATH_SIZE_MISMATCH : Matrix size check failed

  @par           Scaling and Overflow Behavior
                   The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.15 format.
                   These are multiplied to yield a 2.30 intermediate result and this is shifted with saturation to 1.15 format.
 */
#if defined(ARM_MATH_MVEI)
arm_status arm_mat_scale_q15(
	const arm_matrix_instance_q15 *pSrc,
	q15_t                     scaleFract,
	int32_t                   shift,
	arm_matrix_instance_q15 *pDst)
{
	arm_status status;                             /* Status of matrix scaling */
	q15_t *pIn = pSrc->pData;       /* input data matrix pointer */
	q15_t *pOut = pDst->pData;      /* output data matrix pointer */
	uint32_t  numSamples;           /* total number of elements in the matrix */
	uint32_t  blkCnt;               /* loop counters */
	q15x8_t vecIn, vecOut;
	q15_t const *pInVec;
	int32_t totShift = shift + 1;   /* shift to apply after scaling */

	pInVec = (q15_t const *) pIn;

#ifdef ARM_MATH_MATRIX_CHECK

	/* Check for matrix mismatch condition */
	if ((pSrc->numRows != pDst->numRows) ||
		(pSrc->numCols != pDst->numCols)) {
		/* Set status as ARM_MATH_SIZE_MISMATCH */
		status = ARM_MATH_SIZE_MISMATCH;
	} else

#endif /* #ifdef ARM_MATH_MATRIX_CHECK */

	{
		/*
		 * Total number of samples in the input matrix
		 */
		numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
		blkCnt = numSamples >> 3;
		while (blkCnt > 0U) {
			/*
			 * C(m,n) = A(m,n) * scale
			 * Scaling and results are stored in the destination buffer.
			 */
			vecIn = vld1q(pInVec);
			pInVec += 8;

			/* multiply input with scaler value */
			vecOut = vmulhq(vecIn, vdupq_n_s16(scaleFract));
			/* apply shifting */
			vecOut = vqshlq_r(vecOut, totShift);

			vst1q(pOut, vecOut);
			pOut += 8;

			/*
			 * Decrement the blockSize loop counter
			 */
			blkCnt--;
		}
		/*
		 * tail
		 * (will be merged thru tail predication)
		 */
		blkCnt = numSamples & 7;
		if (blkCnt > 0U) {
			mve_pred16_t p0 = vctp16q(blkCnt);
			vecIn = vld1q(pInVec);
			pInVec += 8;
			vecOut = vmulhq(vecIn, vdupq_n_s16(scaleFract));
			vecOut = vqshlq_r(vecOut, totShift);
			vstrhq_p(pOut, vecOut, p0);
		}
		/* Set status as ARM_MATH_SUCCESS */
		status = ARM_MATH_SUCCESS;
	}

	/* Return to application */
	return (status);
}

#else
arm_status arm_mat_scale_q15(
	const arm_matrix_instance_q15 *pSrc,
	q15_t                     scaleFract,
	int32_t                   shift,
	arm_matrix_instance_q15 *pDst)
{
	q15_t *pIn = pSrc->pData;                      /* Input data matrix pointer */
	q15_t *pOut = pDst->pData;                     /* Output data matrix pointer */
	uint32_t numSamples;                           /* Total number of elements in the matrix */
	uint32_t blkCnt;                               /* Loop counter */
	arm_status status;                             /* Status of matrix scaling */
	int32_t kShift = 15 - shift;                   /* Total shift to apply after scaling */

#if defined (ARM_MATH_LOOPUNROLL) && defined (ARM_MATH_DSP)
	q31_t inA1, inA2;
	q31_t out1, out2, out3, out4;                  /* Temporary output variables */
	q15_t in1, in2, in3, in4;                      /* Temporary input variables */
#endif

#ifdef ARM_MATH_MATRIX_CHECK

	/* Check for matrix mismatch condition */
	if ((pSrc->numRows != pDst->numRows) ||
		(pSrc->numCols != pDst->numCols)) {
		/* Set status as ARM_MATH_SIZE_MISMATCH */
		status = ARM_MATH_SIZE_MISMATCH;
	} else

#endif /* #ifdef ARM_MATH_MATRIX_CHECK */

	{
		/* Total number of samples in input matrix */
		numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;

#if defined (ARM_MATH_LOOPUNROLL)

		/* Loop unrolling: Compute 4 outputs at a time */
		blkCnt = numSamples >> 2U;

		while (blkCnt > 0U) {
			/* C(m,n) = A(m,n) * k */

#if defined (ARM_MATH_DSP)
			/* read 2 times 2 samples at a time from source */
			inA1 = read_q15x2_ia((q15_t **) &pIn);
			inA2 = read_q15x2_ia((q15_t **) &pIn);

			/* Scale inputs and store result in temporary variables
			 * in single cycle by packing the outputs */
			out1 = (q31_t)((q15_t)(inA1 >> 16) * scaleFract);
			out2 = (q31_t)((q15_t)(inA1) * scaleFract);
			out3 = (q31_t)((q15_t)(inA2 >> 16) * scaleFract);
			out4 = (q31_t)((q15_t)(inA2) * scaleFract);

			/* apply shifting */
			out1 = out1 >> kShift;
			out2 = out2 >> kShift;
			out3 = out3 >> kShift;
			out4 = out4 >> kShift;

			/* saturate the output */
			in1 = (q15_t)(__SSAT(out1, 16));
			in2 = (q15_t)(__SSAT(out2, 16));
			in3 = (q15_t)(__SSAT(out3, 16));
			in4 = (q15_t)(__SSAT(out4, 16));

			/* store result to destination */
			write_q15x2_ia(&pOut, __PKHBT(in2, in1, 16));
			write_q15x2_ia(&pOut, __PKHBT(in4, in3, 16));

#else
			*pOut++ = (q15_t)(__SSAT(((q31_t)(*pIn++) * scaleFract) >> kShift, 16));
			*pOut++ = (q15_t)(__SSAT(((q31_t)(*pIn++) * scaleFract) >> kShift, 16));
			*pOut++ = (q15_t)(__SSAT(((q31_t)(*pIn++) * scaleFract) >> kShift, 16));
			*pOut++ = (q15_t)(__SSAT(((q31_t)(*pIn++) * scaleFract) >> kShift, 16));
#endif

			/* Decrement loop counter */
			blkCnt--;
		}

		/* Loop unrolling: Compute remaining outputs */
		blkCnt = numSamples % 0x4U;

#else

		/* Initialize blkCnt with number of samples */
		blkCnt = numSamples;

#endif /* #if defined (ARM_MATH_LOOPUNROLL) */

		while (blkCnt > 0U) {
			/* C(m,n) = A(m,n) * k */

			/* Scale, saturate and store result in destination buffer. */
			*pOut++ = (q15_t)(__SSAT(((q31_t)(*pIn++) * scaleFract) >> kShift, 16));

			/* Decrement loop counter */
			blkCnt--;
		}

		/* Set status as ARM_MATH_SUCCESS */
		status = ARM_MATH_SUCCESS;
	}

	/* Return to application */
	return (status);
}
#endif /* defined(ARM_MATH_MVEI) */

/**
  @} end of MatrixScale group
 */
